Recently, existing CRT display monitors have been rapidly replaced by LCD monitors characterized by high definition.
Such an LCD monitor is mainly composed of LCD glass and indium tin oxide (ITO). Among these, indium included in ITO is classified as a rare metal that exists in a very small amount on earth, and therefore needs to be recycled.
In addition, LCD glass, which accounts for a significant portion of the materials of an LCD monitor, should be recycled once it is discarded, but is simply incinerated or buried because the economic efficiency of recycling thereof is low due to the insufficient development of relevant technology, and significant processing costs are incurred for incineration or landfill.
Meanwhile, in the case of South Korea, which is an LCD manufacturing powerhouse, a great amount of waste LCD glass is generated in the course of production of related products by “S” company and “L” company, which have large-scale LCD production facilities. Thus, considering the arrival of the replacement cycle of domestic LCD products, the amount of waste LCD glass that is generated is expected to increase rapidly.
Therefore, measures to dispose of waste LCD glass have been proposed. According to WEEE regulations published by the European Union (EU) in early 2003, with relation to electronic products, it is stipulated that, by 2006, the recycling rate for electronic products should be 75% or more and the legal recycling rate under extended producer responsibility (EPR) should be 65% or more. In Korea, which is a strong net exporter of LCD related products, it is time to endeavor to raise the rate of recycling of waste LCD glass products in order to increase the competitiveness of production companies and national exports.
To this end, in the respective countries in the world, indium is recovered in the course of recycling waste LCD glass, or recovered materials acquired by physically or chemically treating waste LCD glass are applied to new products.
Meanwhile, lake water (reservoir water), river water, and sewage, used in water supply and drainage, contain floating matter, solids, and bacteria such as colon bacilli, generated from various foreign substances and dirt, in a precipitated or suspended form.
Thus, raw water having such a water quality cannot be used as drinking water or graywater, and requires a separate treatment process.
To this end, recently, physical and chemical treatment methods, such as an aggregation treatment method, a sand filtering method, and the like, have been widely used.
The sand filtering method has a disadvantage in that a filtering speed is slow (within a range from about 120/m3/m2/day to 150/m3/m2/day) because homogenous sand has low porosity of 0.3 to 0.4.
In addition, the sand filtering method incurs excessive installation costs and a large amount of land for filtering facilities, and requires backwashing in order to restore a filtering function because sand is contaminated after a certain amount of time has passed.
However, in the sand filtering method, backwashing is not efficiently performed because the sand is heavy (having a specific gravity of about 2.5) and consumes a lot of power. In order to solve this problem, anthracite (mainly composed of sand and anthracite) has been developed and used, but confers only slight improvement in filtering speed (within a range from about 200/m3/m2/day to 300/m3/m2/day) and still requires excessive installation costs and land for filtering facilities, and moreover still requires backwashing in order to restore a filtering function because it is also contaminated after a certain amount of time has passed.
Therefore, as a solution of the related art, Korean Patent Application No. 2011-0039331 (filed on 27 Apr. 2011) discloses a porous floating filter material, the technical subject of which resides in that a foam is formed using glass and is used for water treatment.
However, this related art is not a system that recycles derelict resources such as waste bottle glass (technology related to washing is not described in the corresponding publication) and is not considered a green technology, and in that there is no treatment plan for pollution, noise generation, or the like in the surrounding environment, which are caused in the processes of crushing, pulverization, mixing agitation, calcination, cooling, and sorting for the manufacture of a filter material.